This invention relates to a spectrophotometer in which the wavelength of the light to be measured and the slit width of the monochromator can automatically be adjusted to a designated value.
Spectrophotometers are provided with a monochromator which comprises an entrance and an exit slit and a dispersing element such as a diffraction grating so arranged as to be automatically or manually set to provide a designated wavelength at the exit slit. Practically, however, the wavelength actually obtained at the exit slit is more or less displaced from the designated wavelength. In other words, there always exists an error in wavelength selection. In the spectrophotometer in which the monochromator is automatically set to a designated wavelength, it is necessary to correct the above-mentioned error. Manual correction of the error by the operator is not only troublesome but also time-consuming.
Accordingly, the primary object of the invention is to provide a spectrophotometer in which errors in wavelength selection can automatically be corrected.